1. Field of the Invention
The present invention relates to a packing structure and a packing member made of a corrugated cardboard (hereinafter referred to as a corrugated-cardboard packing member).
2. Description of the Related Art
Conventionally, in a packing structure in which various devices such as electric products and their attachments are packed, a packing member holding a product and its attachment(s) is arranged within a corrugated cardboard box so that they are immovable. A previously known packing member is a packing member made by molding plastic foam such as styrofoam plastic, or a packing member of corrugated cardboard (for example, See JP-UM-A-6-14072, JP-UM-A-6-020279, and JP-UM-A-6-044773).
The documents JP-UM-A-6-14072, JP-UM-A-6-020279, and JP-UM-A-6-044773 disclose a corrugated cardboard packing member which uses, as a shock absorber, a box-like portion formed by bending one or more corrugated cardboard sheets.
FIG. 6 is a schematic view of an exemplary conventional packing structure. Referring to FIG. 6, an explanation will be given of a conventional packing structure 100. The conventional packing structure 100, as seen from FIG. 6, includes a corrugated cardboard box 101, and a pair of styrofoam members 110 and a corrugated-cardboard packing member 120 which serve as packing members arranged within the corrugated cardboard box 101. The packing member 120 is arranged between the upper surface of the pair of styrofoam members 110 and the upper inner surface of the corrugated cardboard box 101 and holds an attachment 160.
FIG. 7 is a front view of the styrofoam member shown in FIG. 6. FIG. 8 is a left side view of FIG. 7. FIG. 9 is a top view of FIG. 8. Referring to FIGS. 6 to 9, the conventional styrofoam member 110 includes a concave portion 111 for holding the side of a product 150, projections 112 and 113 formed on the upper surface, projections 114 formed on the rear surface, and curved sides 115. The projections 112 and 113 formed on the upper surface serve to support the lower surface of the corrugated-cardboard packing member 120. The projections 114 formed on the rear surface of the styrofoam member 110 are located to be in contact with the inner side face of the corrugated cardboard box 101.
FIG. 10 is a perspective view of the conventional corrugated-cardboard packing member shown in FIG. 6. FIG. 11 is a perspective view of the conventional corrugated-cardboard packing member shown in FIG. 10. FIG. 12 is a perspective view for explaining the extending direction of cores of a corrugated cardboard sheet in the conventional corrugated-cardboard packing member shown in FIG. 11. Referring to FIGS. 6, 10 and 11, the conventional corrugated-cardboard packing member 120 includes a bottom housing portion 121, a pair of spacer portions 122, a pair of folding portions 123 and tip projecting portions 124.
The pair of spacer portions 122 are formed by bending both ends of the bottom housing portion 121 in a square shape and arranged to remove the gap between the upper surface of the styrofoam members 110 and the upper inner surface of the corrugated cardboard box 110. The pair of folding portions 123 are formed by bending both ends of the bottom housing portion 121 in a direction orthogonal to the direction of extension of the spacer portions 122, toward the side opposite to the side where the spacer portions are located. Each of the folding portions 123 has an arch shape. The inner side faces 123a of the folding portion 123 are located to be in contact with the curved sides of the styrofoam members 110, respectively. The tip projecting portions 124 are formed to project outwardly from the spacer portions 122 in such a manner that the tips of both ends of the sides of forming the spacer portions 121 are inserted into cutting portions 121a formed in the bottom housing portion 121, respectively. Additionally, the cores 120a of the corrugated cardboard sheet which constitutes the conventional corrugated-cardboard packing member 120 extend in a direction of arrow A illustrated in FIGS. 11 and 12.
FIG. 13 is a view showing the arrangement relationship between the conventional corrugated-cardboard packing member and the pair of styrofoam members illustrated in FIG. 6. Referring to FIGS. 6 and 13, in the conventional packing structure 100, when shock is applied to the corrugated cardboard box 101, the pair of styrofoam members 110 and corrugated-cardboard packing member 120 were caused to have a shock absorbing function. Specifically, the styrofoam member 110, which is elastically deformed to a certain degree when it receives the shock, has the shock absorbing function. The corrugated-cardboard packing member 120 arranged on the conventional styrofoam members 110 has the function of absorbing the shock through elastic deformation of the square spacer portions 122.
However, the conventional packing structure 100 has the following inconvenience. Namely, in the conventional packing structure 100, since the cores 120a of the corrugated cardboard sheet constituting the corrugated-cardboard member 120 (FIG. 12) are formed to extend in the direction of arrow A, when force is applied from above to the spacer portions 122 of the corrugated cardboard member 120, the sides 122a in a vertical direction of the square spacer portions 122 are likely to be not deformed elastically but bent. When the sides 122a in the vertical direction of the spacer portions 122 are bent, a problem occurs that the shock absorbing function of the spacer portions 122 is deteriorated. Further, the When the sides 122a in the vertical direction of the spacer portions 122 are bent, the height of the spacer portions 122 is reduced so that a space or gap is generated between the upper inner face of the corrugated cardboard box 101 and upper face of the spacer portions 122. Therefore, since the pair of styrofoam members 110 are likely to move vertically, a problem occurs that the product 150 falls out from the pair of styrofoam members 110 owing to the vertical movement of the pair of styrofoam members 110.
The conventional packing structure 100 shown in FIG. 6 has also the following inconvenience. Namely, when the shock in a horizontal direction is applied to the corrugated cardboard box 101, the end of one of the styrofoam member 110 is likely to move toward the opposite styrofoam member 110 (direction of arrow C in FIGS. 6 and 9). Thus, also when the end of one of the styrofoam members 110 moves in the direction of arrow C, a problem occurs that the product 150 falls.
Further, the conventional packing structure has also an inconvenience that the bottom housing portion 121 of the conventional corrugated-cardboard packing member 120, which is formed of a single corrugated-cardboard sheet, is lack of flexibility. The conventional packing structure also presents a problem that it is difficult to provide the conventional corrugated-cardboard packing member 120 with a sufficient shock absorbing function owing to the reduction of the shock absorbing function of the corrugated-cardboard packing member 120 due to the bending of the spacer portions 122 and lack of the flexibility of the bottom housing portion 121.
The conventional packing structure 100 shown in FIG. 6 has also the following inconvenience. When strong shock is applied to the corrugated cardboard box 101 owing to its dropping, great force is applied to the portion where the inner side faces 123a of the folding portion 123 of the corrugated-cardboard packing member 120 and the sides 115 of the styrofoam member 100 are in contact with each other so that excessive pushing force in a direction of arrow B in FIGS. 7 to 9 is applied to the sides of the styrofoam member 110. Owing to the excessive pushing force in this direction of arrow B, the sides of the styrofoam member 110 may be damaged as indicated in two-dot chain line in FIGS. 8 and 9. Also when the sides 115 of the styrofoam member 110 are damaged, the styrofoam member 110 is likely to move in a direction of arrow D in FIG. 9 so that the product 150 (FIG. 6) supported by the styrofoam members 110 falls from the styrofoam members 110.
Further, in the conventional box-like corrugated-cardboard packing member disclosed in the documents JP-UM-A-6-14072, JP-UM-A-6-020279, and JP-UM-A-6-044773, the direction of extending the cores of the corrugated cardboard sheet is not taken into consideration. Therefore, in the case where the direction of extending the cores of the corrugated cardboard sheet is longitudinal of the box portion, when force is applied vertically (short-length direction) to the box portion, the box portion may not deformed elastically but bent. In this case, like the conventional corrugated-cardboard packing member 120 shown in FIG. 10, a problem occurs that the shock absorbing function of the box portion is deteriorated. Further, like the conventional corrugated-cardboard packing member 120 shown in FIG. 10, the corrugated-cardboard packing member disclosed in the documents JP-UM-A-6-14072, JP-UM-A-6-020279, and JP-UM-A-6-044773 have an inconvenience that the bottom housing portion, which is formed of a single corrugated-cardboard sheet, is lack of flexibility. Thus, in the corrugated-cardboard packing member disclosed in the above described documents, it is difficult to provide the bottom housing portion with a sufficient shock absorbing function.